Isolated testicular vasculitis mimicking a testicular neoplasm

A 19 year old man presented with unilateral testicular swelling and pain. An initial diagnosis of epididymo-orchitis was modified to a presumed testicular neoplasm following ultrasonography. The final diagnosis of isolated testicular vasculitis was established following histological examination of the orchidectomy specimen. Staining for antineutrophil cytoplasmic antibodies was negative. Despite immunosuppressive treatment, the patient developed further symptoms affecting the remaining testis one year later. He responded well to an increase in immunosuppressive therapy and has remained asymptomatic 18 months from diagnosis. Symptomatic vasculitis confined to the testis is extremely rare, but must be considered in the differential diagnosis of testicular swelling and may be the presenting feature of a systemic vasculitis such as polyarteritis nodosa. The risk of progression to systemic disease in such cases is unknown. Immunosuppressive therapy must be considered carefully and long term follow up is important.